Markers In Healthy Adults Research Articles

Walnut Consumption Alters the Gastrointestinal Microbiota, Microbially Derived Secondary Bile Acids, and Health Markers in Healthy Adults: A Randomized Controlled Trial

BackgroundEpidemiologic data suggest that diets rich in nuts have beneficial health effects, including reducing total and cause-specific mortality from cancer and heart disease. Although there is accumulating preclinical evidence that walnuts beneficially affect the gastrointestinal microbiota and gut and metabolic health, these relations have not been investigated in humans.ObjectiveWe aimed to assess the impact of walnut consumption on the human gastrointestinal microbiota and metabolic markers of health.MethodsA controlled-feeding, randomized crossover study was undertaken in healthy men and women [n = 18; mean age = 53.1 y; body mass index (kg/m2): 28.8]. Study participants received isocaloric diets containing 0 or 42 g walnuts/d for two 3-wk periods, with a 1-wk washout between diet periods. Fecal and blood samples were collected at baseline and at the end of each period to assess secondary outcomes of the study, including effects of walnut consumption on fecal microbiota and bile acids and metabolic markers of health.ResultsCompared with after the control period, walnut consumption resulted in a 49–160% higher relative abundance of Faecalibacterium, Clostridium, Dialister, and Roseburia and 16–38% lower relative abundances of Ruminococcus, Dorea, Oscillospira, and Bifidobacterium (P < 0.05). Fecal secondary bile acids, deoxycholic acid and lithocholic acid, were 25% and 45% lower, respectively, after the walnut treatment compared with the control treatment (P < 0.05). Serum LDL cholesterol and the noncholesterol sterol campesterol concentrations were 7% and 6% lower, respectively, after walnut consumption compared with after the control treatment (P < 0.01).ConclusionWalnut consumption affected the composition and function of the human gastrointestinal microbiota, increasing the relative abundances of Firmicutes species in butyrate-producing Clostridium clusters XIVa and IV, including Faecalibacterium and Roseburia, and reducing microbially derived, proinflammatory secondary bile acids and LDL cholesterol. These results suggest that the gastrointestinal microbiota may contribute to the underlying mechanisms of the beneficial health effects of walnut consumption. This trial was registered at www.clinicaltrials.gov as NCT01832909.

Effect of Loquat Leaf Extract on Muscle Strength, Muscle Mass, and Muscle Function in Healthy Adults: A Randomized, Double-Blinded, and Placebo-Controlled Trial.

Ursolic acid (UA) is the major active component of the loquat leaf extract (LLE) and several previous studies have indicated that UA may have the ability to prevent skeletal muscle atrophy. Therefore, we conducted a randomized, double-blind, and placebo-controlled study to investigate the effects of the LLE on muscle strength, muscle mass, muscle function, and metabolic markers in healthy adults; the safety of the compound was also evaluated. We examined the peak torque/body weight at 60°/s knee extension, handgrip strength, skeletal muscle mass, physical performance, and metabolic parameters at baseline, as well as after 4 and 12 weeks of intervention. Either 500 mg of LLE (50.94 mg of UA) or a placebo was administered to fifty-four healthy adults each day for 12 weeks; no differences in muscle strength, muscle mass, and physical performance were observed between the two groups. However, the right-handgrip strength of female subjects in the LLE group was found to be significantly better than that of subjects in the control group (P = 0.047). Further studies are required to determine the optimal dose and duration of LLE supplementation to confirm the first-stage study results for clinical application. ClinicalTrials.gov Identifier is NCT02401113.

Association between serum fatty acid composition and innate immune markers in healthy adults.

BACKGROUND/OBJECTIVESSupplementation with n-3 polyunsaturated fatty acids (PUFAs) has been shown to generally decrease levels of innate immune markers and inflammatory cytokines, but the specific associations between blood levels of PUFAs and those of innate immune markers have not been investigated. Thus, the present study was conducted to test the hypothesis that innate immune markers as well as cytokines are negatively associated with n-3 PUFAs but positively associated with n-6 PUFAs in healthy adults.MATERIALS/METHODSOne hundred sixty-five healthy Korean adults aged 25-70 years old were included in this cross-sectional study.RESULTSSerum levels of n-3 PUFAs, such as 18:3n3, 20:5n3, 22:5n3, and 22:6n3 were negatively correlated with eosinophil and basophil counts and TNF-α, IFN-γ, IL-4, and IL-10 levels. Multivariate analysis also showed that serum levels of n-3 PUFAs were negatively associated with monocyte, eosinophil, and basophil counts and TNF-α, IFN-γ, IL-4, and IL-12 levels. Additionally, the ratio of 20:4n6 to 20:5n3 was positively correlated with eosinophil counts and associated with TNF-α, IFN-γ, and IL-4 levels. However, NK cell activity was not associated with serum fatty acid composition.CONCLUSIONSInnate immune markers such as eosinophil, monocyte, and basophil counts were inversely associated with serum levels of n-3 PUFAs, but were positively associated with the 20:4n6/20:5n3 ratio in this population.

Effects of regular consumption of vitamin C-rich or polyphenol-rich apple juice on cardiometabolic markers in healthy adults: a randomized crossover trial

The aim of the present study was to investigate the effects of the consumption of two cloudy apple juices with different polyphenol and vitamin C contents on antioxidant status, cardiometabolic and inflammation markers in healthy young adults. Twenty subjects, aged 21-29 years, completed a randomized crossover study. At each 4-week intervention period, the volunteers randomly consumed two glasses (2 × 250 mL/day) of either a vitamin C-rich apple juice (VCR) (60 mg/L vitamin C and 510 mg catechin equivalent/L) or a polyphenol-rich (PR) juice (22 mg/L vitamin C and 993 mg catechin equivalent/L). Blood and urine samples were collected throughout the study, and markers of antioxidant status, glucose metabolism, lipid profile and inflammation were measured. The comparison of the post-intervention minus pre-intervention change revealed differential results in HOMA index, total cholesterol, ICAM-1 and VCAM-1 (P < 0.05) across juices. During the VCR period, plasma antioxidant activity (FRAP) increased (P = 0.031), while ICAM-1 and total cholesterol showed a trend to decrease (P = 0.060 and P = 0.094, respectively). During the PR period, plasma insulin and HOMA increased, and total glutathione decreased (P < 0.05). A joint consumption of apple juice natural antioxidants such as vitamin C and polyphenols might provide mild favorable effects on cardiometabolic markers, as compared to apple polyphenols alone.

N‐3 Polyunsaturated Fatty Acids: Relationship to Inflammation in Healthy Adults and Adults Exhibiting Features of Metabolic Syndrome

Individuals with metabolic syndrome (MetS) have a higher risk of type 2 diabetes and cardiovascular disease, therefore, research has been directed at reducing various components that contribute to MetS and associated metabolic impairments, including chronic low-grade inflammation. Epidemiological, human, animal and cell culture studies provide evidence that dietary n-3 polyunsaturated fatty acids (n-3 PUFA), including alpha-linolenic acid (18:3n-3, ALA), eicosapentaenoic acid (20:5n-3, EPA) and/or docosahexaenoic acid (22:6n-3, DHA) may improve some of the components associated with MetS. The current review will discuss recent evidence from human observational and intervention studies that focused on the effects of ALA, EPA or DHA on inflammatory markers in healthy adults and those with one or more features of MetS. Observational studies in healthy adults support the recommendation that a diet rich in n-3 fatty acids may play a role in preventing and reducing inflammation, whereas intervention studies in healthy adults have yielded inconsistent results. The majority of intervention studies in adults with features of MetS have reported a benefit for some inflammatory measures; however, other studies using high n-3 fatty acid doses and long supplementation periods have reported no effect. Overall, the data reviewed herein support recommendations for regular fatty fish consumption and point toward health benefits in terms of lowering inflammation in adults with one or more features of MetS.

In-Traffic Air Pollution Exposure and CC16, Blood Coagulation, and Inflammation Markers in Healthy Adults

Background: Exposure to traffic-related air pollution is a risk factor for cardiovascular events, probably involving mechanisms of inflammation and coagulation. Little is known about effects of the short exposures encountered while participating in traffic.Objectives: The objective of the study was to examine effects of exposure of commuters to air pollution on cardiovascular biomarkers.Methods: Thirty-four healthy adult volunteers commuted for 2 hr by bus, car, or bicycle during the morning rush hour. During the commute, exposure to particle number, particulate matter (PM) ≤ 2.5 µm in aerodynamic diameter (PM2.5), PM ≤ 10 µm in diameter (PM10), and soot was measured. We estimated inhaled doses based on heart rate monitoring. Shortly before exposure and 6 hr after exposure, blood samples were taken and analyzed for CC16 (Clara cell protein 16), blood cell count, coagulation markers, and inflammation markers. Between June 2007 and June 2008, 352 pre- and postexposure blood samples were collected on 47 test days. We used mixed models to analyze the associations between exposure and changes in health parameters.Results: We observed no consistent associations between the air pollution exposures and doses and the various biomarkers that we investigated.Conclusions: Air pollution exposure during commuting was not consistently associated with acute changes in inflammation markers, blood cell counts, or blood coagulation markers.

Dietary choline and betaine intakes in relation to concentrations of inflammatory markers in healthy adults: the ATTICA study

Background:Choline and betaine are found in a variety of plant and animal foods and were recently shown to be associated with decreased homocysteine concentrations. Objective:The scope of this work was to investigate the associations between dietary choline and betaine consumption and various markers of low-grade systemic inflammation. Design:Under the context of a cross-sectional survey that enrolled 1514 men (18–87 y of age) and 1528 women (18–89 y of age) with no history of cardiovascular disease (the ATTICA Study), fasting blood samples were collected and inflammatory markers were measured. Dietary habits were evaluated with a validated food-frequency questionnaire, and the intakes of choline and betaine were calculated from food-composition tables. Results:Compared with the lowest tertile of choline intake (<250 mg/d), participants who consumed >310 mg/d had, on average, 22% lower concentrations of C-reactive protein (P < 0.05), 26% lower concentrations of interleukin-6 (P < 0.05), and 6% lower concentrations of tumor necrosis factor-α (P < 0.01). Similarly, participants who consumed >360 mg/d of betaine had, on average, 10% lower concentrations of homocysteine (P < 0.01), 19% lower concentrations of C-reactive protein (P < 0.1), and 12% lower concentrations of tumor necrosis factor-α (P < 0.05) than did those who consumed <260 mg/d. These findings were independent of various sociodemographic, lifestyle, and clinical characteristics of the participants. Conclusions:Our results support an association between choline and betaine intakes and the inflammation process in free-eating and apparently healthy adults. However, further studies are needed to confirm or refute our findings.

N‐3 Fatty Acid Enriched Egg Decreases C‐Reactive Protein in Healthy Adults

Both n-3 and n-6 polyunsaturated fatty acids are substrates for inflammatory factors. To date only a few studies have investigated the effect of whole food sources of α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on inflammatory markers in healthy adults. We compared the effect of walnuts (source of linoleic acid and ALA), n-3 fatty acid enriched eggs (source of DHA and ALA) and organic egg (low in n-3 and n-6 fatty acids) on selected inflammatory markers in 20 healthy, free-living, lacto-ovo vegetarians. Subjects were randomly assigned to an organic egg (6/wk), n-3 fatty acid enriched egg (6/wk), or walnut (170 g/wk) treatment for 8 weeks each in a crossover design with 4-wk washout between treatments. Plasma interleukin 6, interleukin 1β, C-reactive protein (CRP), tumor necrosis factor α, E-selectin, and intercellular adhesion molecule-1 were measured at end of each treatment period. Mixed linear models were used to analyze the treatment effects. A significant decrease in CRP was seen in the n-3 fatty acid enriched egg treatment group compared to the organic egg (p<0.0022; GM 94.65 μg/dL, 95% CI 99.29, 59.85) and walnut treatment group (p<0.0062; GM 92.26 μg/dL 95% CI 98.90, 45.80). All other inflammatory factors were not significantly different. We conclude that the long-chain n-3 fatty acids in the egg may be responsible for the low CRP levels. Support: American Egg Board, Agriculture Research Initiative, California

Nitrogen Metabolism and Bone Metabolism Markers in Healthy Adults during 16 Weeks of Bed Rest

The associations between nitrogen metabolism and bone turnover during bed rest are still not completely understood. We measured nitrogen balance (nitrogen intake minus urinary nitrogen excretion) and biochemical metabolic markers of calcium and bone turnover in six males before head-down tilt bed rest (baseline), during 2, 10, and 14 weeks of immobilization, and after reambulation. The changes in nitrogen balance were highest between baseline and week 2 (net change, -5.05 +/- 1.30 g/day; 3.6 +/- 0.6 g/day at baseline vs -1.45 +/- 1.3 g/day at week 2; P<0.05). In parallel, serum intact osteocalcin (a marker of bone formation) was already reduced and renal calcium and phosphorus excretions were increased at week 2 (P <0.05). Fasting serum calcium and phosphorus values and renal excretion of N-telopeptide (a bone resorption marker) were enhanced at weeks 10 and 14 (P <0.05-0.001), whereas serum concentrations of parathyroid hormone, calcitriol, and type I collagen propeptide (a marker of bone collagen formation) were decreased at week 14 (P <0.05-0.01). Significant associations were present between changes of serum intact osteocalcin and 24-h calcium excretion (P <0.001), nitrogen balance and 24-h phosphorus excretion (P <0.001), nitrogen balance and renal N-telopeptide excretion (P <0.05), and between serum osteocalcin and nitrogen balance (P <0.025). Bone formation decreases rapidly during immobilization in parallel with a higher renal excretion of intestinally absorbed calcium. These changes appear in association with the onset of a negative nitrogen balance, but decreased bone collagen synthesis and enhanced collagen breakdown occur after a time lag of several weeks.